Percutaneous endobiliary radiofrequency ablation with stent placement in type IV hilar cholangiocarcinoma: A prospective comparison with stent placement alone

OBJECTIVES

This study aimed to compare the safety and effectiveness of percutaneous endobiliary radiofrequency ablation with stent placement (RFA group) versus stent placement alone (stent group) in patients with type IV hilar cholangiocarcinoma.

METHODS

This prospective nonrandomized study was conducted between October 2021 and April 2023. The study included 56 participants (33 men and 23 women, median age 73 years) who underwent percutaneous endobiliary RFA with stent placement (n = 25) or stent placement alone (n = 31) for type IV hilar cholangiocarcinoma. The primary end point was stent patency, while the secondary end points were procedure-related adverse events (AE) and overall survival.

RESULTS

The percutaneous endobiliary RFA and/or stent placement were successfully completed in all patients in both groups. The median stent patency rate was higher in the RFA group than the stent group (188 days vs. 155 days, p = 0.048). There were no differences in AEs (grade 1 [5 in RFA group vs. 5 in stent group, p = 0.74] and grade 2 AEs [2 vs. 4, p = 0.68]) and patients' survival (median 222 days vs. 214 days, p = 0.49) between the two groups.

CONCLUSIONS

In patients with type IV hilar cholangiocarcinoma, percutaneous endobiliary RFA with stent placement may improve stent patency without increasing the risk of AEs compared to stent placement alone.

Superselective Ablative Chemo-ethanol Embolization for Recurrent Single Hepatocellular Carcinoma: A Six-Month Outcome Analysis

Background/Aim

To evaluate the safety and effectiveness of superselective ablative chemoethanol embolization (SACE) for the treatment of patients with recurrent single hepatocellular carcinoma (rHCC).

Materials and Methods

This retrospective study included 22 patients (19 men, median age 63 [range 38-86 y]) with Child-Pugh class of A/B/C (16/3/3) that underwent SACE between January and June 2023 for recurrent single HCCs measuring ≤ 5 cm in diameter using a mixture of 99% Ethanol and ethiodized oil/doxorubicin emulsion. The primary endpoint was the 6-month tumor response, and the secondary endpoints were the 1-month tumor response and treatment-related safety. This study was approved by our institutional review board, and the requirement for informed consent was waived.

Results

SACE was successfully performed in 22 (95.2%) patients. The complete response rates at 1-month and 6-month after treatment were 100% and 83.3%, respectively. At 6-month, local tumor progression occurred in one patient and intrahepatic distant metastasis was found in 6 (30%) patients. No 6-month mortalities were reported. No adverse events greater than grade 2 or laboratory deteriorations were observed. Biliary complications or liver abscesses were not observed.

Conclusion

SACE for a single rHCC was highly effective in achieving a favorable 6-month tumor response and showed acceptable adverse events. However, further prospective studies are required to verify these findings.

Development of a Rabbit Iliac Arterial Stenosis Model Using a Controlled Cholesterol Diet and Pullover Balloon Injury

Purpose

This study aimed to develop a rabbit iliac stenosis model and evaluate the effects of different mechanical injury techniques on the degree of arterial stenosis.

Materials and Methods

Eighteen rabbits were divided into three groups: cholesterol-fed with pullover balloon injury (group A; n = 6), cholesterol-fed with localized balloon dilatation (group B; n = 6), and chow-diet with pullover balloon injury (group C; n = 6). After baseline angiography, the left iliac arteries of all rabbits were injured with a 3 × 10 mm noncompliant balloon using either a wide pullover technique (groups A and C) or a localized balloon dilatation technique (group B). A nine-week follow-up angiography was performed, and the angiographic late lumen loss and percentage of stenosis were compared.

Results

Group A exhibited the most severe late lumen loss (A vs. B, 0.67 ± 0.13 vs. 0.04 ± 0.13 mm, p < 0.0001; A vs. C, 0.67 ± 0.13 vs. 0.26 ± 0.29 mm, p < 0.05; stenosis percentage 32.02% ± 6.54%). In contrast, group B showed a minimal percentage of stenosis (1.75% ± 6.55%).

Conclusion

Pullover-balloon injury can lead to significant iliac artery stenosis in rabbits with controlled hypercholesterolemia. This model may be useful for elucidating the pathogenesis of atherosclerosis and for evaluating the efficacy of novel therapeutic interventions.

Lymphangiogenesis after nonvascularized lymph node transplantation: Lymphangiographic findings in mice and minipigs

The establishment of new connections after NVLNT (non-vascularized lymph node transplantation) is still poorly understood. The purpose of this study was to investigate lymphatic connections after NVLNT using lymphangiography. In a mice model, 40 mice were allocated to undergo NVLNT or sham surgery. On day 21 after NVLNT, the lymphatic vessels were observed on near-infrared fluorescence imaging with indocyanine green. In a minipig model, 12 minipigs underwent NVLNT. On day 14 after NVLNT, the transplanted lymph node and donor site were checked by ultrasound, and minipigs with viable transplanted LNs were allocated to lipiodol lymphangiography or MR lymphangiography groups. Transplanted LN engraftment was examined with immunohistochemical staining. After NVLNT in mice, the signal intensities in the popliteal region at 3 minutes and 5 minutes were higher in the transplanted side than the control side (21.3 ± 8.1 vs. 11.0 ± 4.6 at 3 minutes, 26.7 ± 6.8 vs. 19.7 ± 5.9 at 5 minutes), while in the sham group, there were no significant differences between sides. In minipigs, lipiodol lymphangiography (n = 5) showed Lipiodol accumulation in transplanted LNs with innumerable newly formed lymphatic vessels and lymphovenous shunts. MR lymphangiography (n = 5) showed higher enhancement on the transplanted side compared to the control side. Histology showed successful engraftment of transplanted LNs in 16 out of 20 (80%) mice and 9 out of 12 (75%) minipigs. Omnidirectional lymphangiogenesis forming a dense lymphatic network and spontaneous formation of lymphovenous shunts were shown after NVLNT.

Transarterial chemoembolization for hepatocellular carcinoma: 2023 expert consensus-based practical recommendations of the Korean Liver Cancer Association

Transarterial chemoembolization (TACE) was introduced in 1977 with the administration of chemotherapeutic agent to gelatin sponge particles through the hepatic artery in patients with hepatocellular carcinoma (HCC) and was established as conventional TACE using Lipiodol in the 1980s. In the 2000s, drug-eluting beads were developed and applied clinically. Currently, TACE is a commonly used non-surgical treatment modality for patients with HCC who are unsuitable for curative treatment. Considering the vital role of TACE in the management of HCC, it is crucial to organize current knowledge and expert opinions regarding patient preparation, procedural techniques, and post-treatment care in TACE, which can enhance therapeutic efficacy and safety. A group of 12 experts in the fields of interventional radiology and hepatology, convened by the Research Committee of the Korean Liver Cancer Association (KLCA), has developed expert consensus-based practical recommendations in TACE. These recommendations have been endorsed by the Korean Society of Interventional Radiology and provide useful information and direction in performing TACE procedure as well as pre- and post- procedural patient care.

Denali Inferior Vena Cava Filter Retrieval: Complications and Success Rates

PURPOSE

The present study was to evaluate the outcomes of Denali filter retrieval.

MATERIALS AND METHODS

We retrospectively reviewed 143 patients who received Denali filter insertion from September 2015 to April 2020. Ninety-seven patients who required removal of the filters were include in this study. Filters were retrieved with either standard or advanced techniques. Venography before and after retrieval was obtained to evaluate technical success, complications and duration of filter insertion.

RESULTS

All 97 filters were retrieved successfully without complications. Ninety-two (94.8%) were retrieved with standard technique and 5 filters (5.2%) required the advanced technique. There were two cases with a filter angle greater than 15 degrees. Inferior vena cava penetration was shown in 17 patients (17.5%) on venography but was not associated with contrast media extravasation after filter removal.

CONCLUSION

The Denali filter showed a high rate of successful retrieval without complications. This study adds value to previous studies and trials showing that the Denali filter is a reliable and safe filter that can potentially improve retrieval rates, with increasing use of this device.

Transarterial chemoembolization for hepatocellular carcinoma: 2023 Expert consensus-based practical recommendations of the Korean Liver Cancer Association

Transarterial chemoembolization (TACE) was introduced in 1977 with the administration of chemotherapeutic agent to gelatin sponge particles through the hepatic artery in patients with hepatocellular carcinoma (HCC) and was established as conventional TACE using Lipiodol in the 1980s. In the 2000s, drug-eluting beads were developed and applied clinically. Currently, TACE is a commonly used non-surgical treatment modality for patients with HCC who are unsuitable for curative treatment. Considering the vital role of TACE in the management of HCC, it is crucial to organize current knowledge and expert opinions regarding patient preparation, procedural techniques, and post-treatment care in TACE, which can enhance therapeutic efficacy and safety. A group of 12 experts in the fields of interventional radiology and hepatology, convened by the Research Committee of the Korean Liver Cancer Association (KLCA), has developed expert consensus-based practical recommendations in TACE. These recommendations have been endorsed by the Korean Society of Interventional Radiology and provide useful information and direction in performing TACE procedure as well as pre- and post- procedural patient care.

Transarterial Chemoembolization for Hepatocellular Carcinoma: 2023 Expert Consensus-Based Practical Recommendations of the Korean Liver Cancer Association

Transarterial chemoembolization (TACE) was introduced in 1977 with the administration of chemotherapeutic agent to gelatin sponge particles through the hepatic artery in patients with hepatocellular carcinoma (HCC) and was established as conventional TACE using Lipiodol in the 1980s. In the 2000s, drug-eluting beads were developed and applied clinically. Currently, TACE is a commonly used non-surgical treatment modality for patients with HCC who are unsuitable for curative treatment. Considering the vital role of TACE in the management of HCC, it is crucial to organize current knowledge and expert opinions regarding patient preparation, procedural techniques, and post-treatment care in TACE, which can enhance therapeutic efficacy and safety. A group of 12 experts in the fields of interventional radiology and hepatology, convened by the Research Committee of the Korean Liver Cancer Association (KLCA), has developed expert consensus-based practical recommendations in TACE. These recommendations have been endorsed by the Korean Society of Interventional Radiology and provide useful information and direction in performing TACE procedure as well as pre- and post-procedural patient care.

The rat eustachian tube: Anatomical, histological, and radiological features

Purpose

This study investigated the anatomical and histological characteristics of the rat Eustachian tube (E-tube) and the feasibility of Eustachian tubography in a rat model.

Materials and methods

Fifteen male Wistar rats were used in this study, and the bilateral E-tubes of each rat were examined. Ten E-tubes were used for anatomical studies, another ten for histological analysis, and the other ten for Eustachian tubography. Five rats were euthanized and decapitated, and ten E-tubes were dissected to describe the anatomy of the E-tube. Ten E-tube specimens obtained from five other rats were sectioned to investigate E-tube histology. Eustachian tubography was performed on the bilateral E-tubes of the other five rats using the trans-tympanic approach.

Results

The rat E-tubes consisted of bony and membranous parts. Cartilage and bone tissue covered only the bony part. The E-tubes' mean diameter and overall length were 2.97 ​mm and 4.96 ​mm, respectively. The tympanic orifices' mean diameter was 1.21 ​mm. The epithelium of E-tubes was mainly composed of pseudostratified ciliated and goblet cells. Eustachian tubography was successfully performed on both sides of the E-tube for each rat. The technical success rate was 100%, the average running time was 4.9 ​min, and no procedure-related complications occurred. On tubography images, the E-tube, tympanic cavity, and nasopharynx could be identified because of the visualization of bony landmarks.

Conclusion

In this study, we described the anatomical and histological features of rat E-tubes. With the aid of these findings, E-tube angiography was successfully performed using a transtympanic approach. These results will facilitate further investigation of E-tube dysfunction.

Comparison of complications between reverse-tapered and nontapered peripherally inserted central catheters

Purpose of this study was to compare the complication rates between reverse-tapered and nontapered peripherally inserted central catheters (PICCs). In total, 407 patients who had an inpatient clinic-based PICC insertion between September 2019 and November 2019 were retrospectively analyzed. Seven PICC types were used (4 reverse tapered: 4-Fr single-lumen (n = 75), 5-Fr single-lumen (n = 78), 5-Fr double-lumen (n = 62), and 6-Fr triple-lumen (n = 61); 3 nontapered: 4-Fr single-lumen (n = 73), 5-Fr double-lumen (n = 30), and 6-Fr triple-lumen (n = 23)). Complications such as periprocedural bleeding, delayed bleeding, inadvertent removal, catheter obstruction by thrombosis, infection, and leakage were investigated. The overall complication rate was 27.1%. The complication rate was significantly higher for nontapered PICCs than reverse-tapered PICCs (50.0% vs 16.7%, P < 0.001). The overall periprocedural bleeding rate was significantly higher for nontapered PICCs than for reverse-tapered PICCs (27.0% vs 6.2%, P <0.001). The overall inadvertent removal rate was significantly higher for nontapered PICCs than for reverse-tapered PICCs (15.1% vs 3.3%, P < 0.001). There were no other significant differences in complication rates. Nontapered PICCs were associated with higher rates of periprocedural bleeding and inadvertent removal than reverse-tapered PICCs.

Using 3D polylines to improve cone-beam CT-guided percutaneous transthoracic needle biopsy

OBJECTIVES

To investigate the diagnostic accuracy of using 3D polylines (3DPs) to improve cone-beam CT (CBCT) virtual navigation (VN)-guided percutaneous transthoracic needle biopsies (PTNB) of pulmonary lesions.

METHODS

From May 2021 to November 2021, patients (81 males and 41 females; age, 65 ± 12 years) who underwent CBCT VN with 3DPs for PTNB of pulmonary lesions were retrospectively reviewed. Fluoroscopic visibility of target lesions was evaluated using captured images from a Bull's eye view. Diagnostic accuracy was calculated, and complications were assessed.

RESULTS

The mean size of biopsied lesions was 23 ± 13 mm (range: 6-75 mm). Overall, 13.9% (17/122) were small pulmonary nodules (diameter ≤1 cm), and 68.0% (83/122) of biopsied lesions were fluoroscopic visible. The overall diagnostic accuracy was 94.3%. The diagnostic accuracy for visible and invisible lesions was 94.0 and 94.9%, respectively (p = 0.843), and 100% for small pulmonary nodules. Major complications occurred in 8.2% (10/122; eight pneumothorax with chest tube insertion, one hemoptysis with transfusion, and one air embolism) of patients.

CONCLUSION

CBCT VN with 3DP guidance provide a real-time outline of pulmonary lesions, thus enabling a reliable and accurate PTNB.

ADVANCES IN KNOWLEDGE

3DP guidance could be useful technique for CBCT-guided PTNB, especially in small pulmonary nodules.

The role of Eustachian tubography and Valsalva CT in Eustachian tube balloon dilation

BACKGROUND

Not many imaging techniques have been reported in Eustachian tube imaging.

PURPOSE

To investigate the role of selective Eustachian tubography (SET) and Valsalva computed tomography (CT) in patients who underwent Eustachian tube balloon dilation (ETBD).

MATERIAL AND METHODS

Eligible patients were aged 18 years and older with chronic Eustachian tube dysfunction who had failed medical treatment. On the day of the procedure, Valsalva CT and SET were performed. Participants underwent fluoroscopic ETBD with a 6×20-mm balloon catheter. Clinical examinations to check for the ability to perform the Valsalva maneuver and ETDQ-7 score change were conducted at one week and then at one, two, and six months. Follow-up Valsalva CT was performed in the one-month follow-up.

RESULTS

A total of 30 ears in 23 patients (16 right ears, 14 left ears; 10 women, 13 men) underwent ETBD from August 2018 to November 2019. Positive CT patency was higher in follow-up Valsalva CT than baseline Valsalva CT (40% and 23.3%, respectively) (P = 0.006). In SET, positive patency was observed in 13 of 25 ears. Response to balloon dilation was observed in 18 of 25 patients. Clinical success was achieved in 16 of 27 ears. Response to balloon dilation was the only significant predictor of clinical success (P = 0.012).

CONCLUSION

SET depicted the lumen of the Eustachian tube; thereby, it could be a potentially valuable tool in ETBD. Valsalva CT provides additional information about the cartilaginous portion of the Eustachian tube.

The efficacy of transcatheter arterial embolization for knee pain on patients with knee osteoarthritis: A case series

BACKGROUND

Knee osteoarthritis (OA) is accompanied by inflammation and angiogenesis. Modifying angiogenesis through transcatheter arterial embolization (TAE) can be a potential treatment for knee OA.

OBJECTIVE

We subjected five OA knees in three patients to TAE and report the results of our post-treatment observations.

CASE DESCRIPTION

Three patients that had experienced knee pain for a minimum of one year prior to the study, and whose pain had persisted despite conservative treatment, were included in this study. Patients more often chose conservative treatment over surgical treatment. Pain and functional scales were evaluated before, immediately, and 1 month after TAE using the Numeric Rating Scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). TAE was performed by an experienced interventional radiologist. The average values of NRS evaluated before and after 5 TAEs were 5.2 before TAE, 3 immediately after TAE, and 3.6 after 1 month of TAE, and the average values of WOMAC were 52, 38.4, and 36.4, respectively. There were no major adverse effects.

CONCLUSION

The examined cases support the conclusion that TAE is an effective treatment for patients with knee OA. Substantial pain relief and WOMAC improvement were observed both immediately and one month after TAE.

Improving the bioavailability of manganese and meat quality of broilers by using hot-melt extrusion nano method

1. Mineral excretion is an issue in the poultry industry. The use of micro minerals in nano form can increase bioavailability and decrease excretion rate. However, information concerning the bioavailability of nano manganese (Mn) in broiler chicks is limited.2. This experiment studied the influences of hot-melt extrusion (HME)-processed manganese sulphate on body weight gain, Mn bioavailability, nutrient digestibility and meat quality in broiler chicks fed a corn-soybean meal-based diet as a starter and grower phase. A total of 700 birds (Ross 308, 1-day-old) were randomly placed in 35 cages (20 birds per cage). The broiler chicks were fed one of seven experimental diets, which consisted of a control (without supplemental Mn), different levels of MnSO₄ (IN-Mn60; 60, 120, and 200 mg/kg), or HME MnSO₄ (HME-Mn; 60, 120, and 200 mg/kg).3. There was an increased serum Mn content in broilers fed diet supplemented with HME-Mn. In the grower phase, increased dietary Mn levels elevated the concentrations in the serum, liver, and tibia. There were increases in the excreta Mn content of broilers fed increasing levels. The supplementation of HME-Mn showed a lower percentage of abdominal fat compared with the IN-Mn treatment diets. Supplementation with HME-Mn decreased intramuscular fat compared with the diets supplemented with IN-Mn. The supplementation of HME-Mn decreased the thiobarbituric acid reactive substances (TBARS) at d 6 of age. The HME-Mn source showed a greater decrease in TBARS compared with the IN-Mn treatment.4. In conclusion, HME processing increased bioavailability and could be used as an environmentally friendly method to facilitate lower levels of Mn in the diet of broiler chickens.

Bronchopleural Fistula after Surgery: Therapeutic Efficacy of Bronchial Occluders

목적

수술 후 발생하는 기관지늑막루에 대한 bronchial occluder device (이하 BOD)의 유용성 및 효과성을 평가하고자 한다.

대상과 방법

2009년도부터 2019년까지 폐암 및 폐결핵으로 수술 후 발생한 7명의 기관지늑막루 환자들 중에 BOD 치료를 실시한 6명의 환자를 대상으로 하였다. 폐암 환자가 5명, 폐결핵 환자는 1명이었다. 남자가 5명, 여자가 1명이었으며 59세에서 74세(평균: 69세)이었다. 진단은 전산화단층기관지 촬영과 기관지내시경으로 실시하였다. 시술은 진단 후 1주에서 2주 사이에 실시하였다. 치료에 사용된 BOD의 기술적 성공 및 임상적 성공을 평가하였다. 시술 후 임상적 치료 효과와 생존 기간 및 부가적인 치료에 대하여 알아보았다.

결과

총 6명 환자 모두에서 시술을 성공적으로 실시하였다. 임상성공 5명에서 있었고, 1명에서는 임상부분성공이 있었다. 임상실패한 경우는 없었다. 기구의 이동이나 천공의 합병증은 없었다. 2명은 전산화단층기관지 촬영으로, 4명은 기관지내시경으로 기관지늑막루를 진단하였다. 수술은 폐엽절제술(lobectomy) 2명, 폐이엽절제술(bilobectomy) 2명, 그리고 전폐절제술(pneumonectomy) 2명이었다. 수술 후 진단까지 걸린 시간은 1개월에서 34개월(평균: 10개월)이었다. 4명(59~103일: 평균 80.5일)은 사망하였고 2명(313일, 3331일)은 생존하였다. 사망 원인이 2명은 기저질환의 악화, 1명은 폐부종 및 흉수, 1명은 폐렴이었다. 한 명에서 부가적인 카테타 배액술, 2명에서 흉관 삽입을 유지하였다.

결론

폐절제 수술 후 발생할 수 있는 기관지늑막루 치료에 있어서 BOD는 유용하고 효과적인 치료 방법이다.

A deep neural network for estimating the bladder boundary using electrical impedance tomography

OBJECTIVE

Accurate bladder size estimation is an important clinical parameter that assists physicians, enabling them to provide better treatment for patients who are suffering from urinary incontinence. Electrical impedance tomography (EIT) is a non-invasive medical imaging method that estimates organ boundaries assuming that the electrical conductivity values of the background, bladder, and adjacent tissues inside the pelvic domain are known a priori. However, the performance of a traditional EIT inverse algorithm such as the modified Newton-Raphson (mNR) for shape estimation exhibits severe convergence problems as it heavily depends on the initial guess and often fails to estimate complex boundaries that require greater numbers of Fourier coefficients to approximate the boundary shape. Therefore, in this study a deep neural network (DNN) is introduced to estimate the urinary bladder boundary inside the pelvic domain.

APPROACH

We designed a five-layer DNN which was trained with a dataset of 15 subjects that had different pelvic boundaries, bladder shapes, and conductivity. The boundary voltage measurements of the pelvic domain are defined as input and the corresponding Fourier coefficients that describe the bladder boundary as output data. To evaluate the DNN, we tested with three different sizes of urinary bladder.

MAIN RESULTS

Numerical simulations and phantom experiments were performed to validate the performance of the proposed DNN model. The proposed DNN algorithm is compared with the radial basis function (RBF) and mNR method for bladder shape estimation. The results show that the DNN has a low root mean square error for estimated boundary coefficients and better estimation of bladder size when compared to the mNR and RBF.

SIGNIFICANCE

We apply the first DNN algorithm to estimate the complex boundaries such as the urinary bladder using EIT. Our work provides a novel efficient EIT inverse solver to estimate the bladder boundary and size accurately. The proposed DNN algorithm has advantages in that it is simple to implement, and has better accuracy and fast estimation.

The Establishment of a Fast and Safe Orthotopic Colon Cancer Model Using a Tissue Adhesive Technique

Purpose

We aimed to develop a novel method for orthotopic colon cancer model, using tissue adhesive in place of conventional surgical method.

Materials and Methods

RFP HCT 116 cell line were used to establish the colon cancer model. Fresh tumor tissue harvested from a subcutaneous injection was grafted into twenty nude mice, divided into group A (suture method) and group B (tissue adhesive method). For the group A, we fixed the tissue on the serosa layer of proximal colon by 8-0 surgical suture. For the group B, tissue adhesive (10 μL) was used to fix the tumor. The mortality, tumor implantation success, tumor metastasis, primary tumor size, and operation time were compared between the two groups. Dissected tumor tissue was analyzed for the histology and immunohistochemistry. Also, we performed tumor marker analysis.

Results

We observed 30% increase in graft success and 20% decrease in mortality, by using tissue adhesive method, respectively. The median colon tumor size was significantly increased by 4 mm and operation time was shortened by 6.5 minutes. The H&E showed similar tumor structure between the two groups. The immunohistochemistry staining for cancer antigen 19-9, carcinoembryonic antigen, cytokeratin 20, and Ki-67 showed comparable intensities in both groups. Real-time quantitative reverse transcription analysis showed eight out of nine tumor markers are unchanged in the tissue adhesive group. Western blot indicated the tissue adhesive group expressed less p-JNK (apototic marker) and more p-MEK/p-p38 (proliferation marker) levels.

Conclusion

We concluded the tissue adhesive method is a quick and safe way to generate orthotopic, colon cancer model.

Simultaneous Estimation of the Fat Fraction and R₂* Via T₂*-Corrected 6-Echo Dixon Volumetric Interpolated Breath-hold Examination Imaging for Osteopenia and Osteoporosis Detection: Correlations with Sex, Age, and Menopause

Objective

To investigate the relationships of T₂^*-corrected 6-echo Dixon volumetric interpolated breath-hold examination (VIBE) imaging-based fat fraction (FF) and R₂^* values with bone mineral density (BMD); determine their associations with sex, age, and menopause; and evaluate the diagnostic performance of the FF and R₂^* for predicting osteopenia and osteoporosis.

Materials and Methods

This study included 153 subjects who had undergone magnetic resonance (MR) imaging, including MR spectroscopy (MRS) and T₂^*-corrected 6-echo Dixon VIBE imaging. The FF and R₂^* were measured at the L4 vertebra. The male and female groups were divided into two subgroups according to age or menopause. Lin's concordance and Pearson's correlation coefficients, Bland-Altman 95% limits of agreement, and the area under the curve (AUC) were calculated.

Results

The correlation between the spectroscopic and 6-echo Dixon VIBE imaging-based FF values was statistically significant for both readers (p_c = 0.940 [reader 1], 0.908 [reader 2]; both p < 0.001). A small measurement bias was observed for the MRS-based FF for both readers (mean difference = −0.3% [reader 1], 0.1% [reader 2]). We found a moderate negative correlation between BMD and the FF (r = −0.411 [reader 1], −0.436 [reader 2]; both p <0.001) with younger men and premenopausal women showing higher correlations. R₂^* and BMD were more significantly correlated in women than in men, and the highest correlation was observed in postmenopausal women (r = 0.626 [reader 1], 0.644 [reader 2]; both p < 0.001). For predicting osteopenia and osteoporosis, the FF had a higher AUC in men and R₂^* had a higher AUC in women. The AUC for predicting osteoporosis was highest with a combination of the FF and R₂^* in postmenopausal women (AUC = 0.872 [reader 1], 0.867 [reader 2]; both p < 0.001).

Conclusion

The FF and R₂^* measured using T₂^*-corrected 6-echo Dixon VIBE imaging can serve as predictors of osteopenia and osteoporosis. R₂^* might be useful for predicting osteoporosis, especially in postmenopausal women.

A Novel Full Sense Device to Treat Obesity in a Porcine Model: Preliminary Results

PURPOSE

To evaluate the technical feasibility, safety, and efficacy of a novel full sense device (FSD) for the treatment of obesity in a porcine model.

MATERIALS AND METHODS

The novel FSD comprised a self-expanding metallic esophageal stent connected to a star-shaped nitinol disk. Three types of FSD were used: fully covered (type A), fully covered with barbs (type B), and uncovered with barbs (type C). Nine juvenile pigs were divided into two groups: FSD (n = 6) and control (n = 3). FSD type A was placed in the FSD group. In case of migration, either FSD type B or type C was then randomly placed. Food intake was monitored daily. Weight changes and ghrelin hormone levels were monitored weekly for 12 weeks.

RESULTS

FSD placement was technically successful in all pigs. All FSDs except one migrated to the stomach within 1 week after placement. The pig in which the FSD was retained showed decreased food intake in the first week after FSD placement, and there was a difference in the final weight between the FSD pig and control pigs. The percentage of weight gain was 116.6% in the control group and 105.3% in the FSD pig.

CONCLUSION

FSD placement under fluoroscopic and endoscopic guidance is technically feasible and safe in a porcine model. The uncovered FSD appears to decrease food intake and reduce the rate of weight gain. However, the high FSD migration rate is not encouraging.

Local Heat Treatment for Suppressing Gastroduodenal Stent-Induced Tissue Hyperplasia Using Nanofunctionalized Self-Expandable Metallic Stent in Rat Gastric Outlet Model

Despite the promising results from the placement of covered or uncovered self-expandable metallic stent (SEMS) as a nonsurgical therapeutic option for the malignant gastric outlet obstruction (GOO), the long patency of the stent is still limited because of stent-induced tissue hyperplasia. Here, a local heat treatment using a nanofunctionalized SEMS is proposed for suppressing stent-induced tissue hyperplasia during GOO treatment. Highly efficient photothermal gold nanoparticle (GNP) transducer-coated SEMSs (GNP-SEMSs) were prepared for local heat treatment in rat gastric outlet. The in vivo heating temperature in rat gastric outlet model was evaluated and compared with in vitro heating temperature. Three groups of our developed 45 rat gastric outlet models were used: group A, noncoated SEMS only; group B, GNP-SEMS plus local heating; and group C, GNP-SEMS only to investigate in vivo efficacy of GNP-SEMS mediated local heating. Ten rats per group were sacrificed for 4 weeks, and five rats per group were sacrificed immediately after local heat treatment. The in vivo heating temperature was found to be 10.8% lower than the in vitro heating temperatures. GNP-SEMSs were successfully placed through a percutaneous approach into the rat gastric outlet (n = 45). The therapeutic effects of GNP-SEMS were assessed by histologic examination including hematoxylin-eosin, Masson trichrome, immunohistochemistry (TUNEL and CD31), and immunofluorescence (Ki67), and the results showed significant prevention of tissue hyperplasia following stent placement without adjacent gastrointestinal tissue damage. GNP-SEMS-mediated local heating could be an alternative therapeutic option for the suppression of tissue hyperplasia following stent placement in benign and malignant GOOs.

EW-7197, a Transforming Growth Factor-Beta Type I Receptor Kinase Inhibitor, Ameliorates Acquired Lymphedema in a Mouse Tail Model

Background: Acquired lymphedema is a common consequence of cancer surgery. Fibrosis is one of the main causes of chronic lymphedema since it hinders lymphatic regeneration and this causes a significant decrease in lymphatic flow and accumulation of excessive protein-rich fluid. The transforming growth factor-β1 (TGF-β1) signaling pathway is known in a process of wound repair and fibrosis. In our study, the purpose was to evaluate the efficacy of EW-7197, a peroral TGF-β type I receptor kinase inhibitor, in treating acquired lymphedema. Methods and Results: For lymphedema mouse tail model, we used 10- to 12-week-old female C57BL/6 mice. The skin was circumferentially excised, making a circular band followed by cauterization of lymphatic collecting vessels. Two groups were made in this study: control and treatment. The treatment group (n = 12) received a solution consisting of 0.1 mL of artificial gastric juice and 20 mg/kg EW-7197 by gavage once daily. For evaluation, tail diameter measurement, fluorescence lymphography, and immunofluorescence images were used. EW-7197 treatment ameliorates acquired lymphedema in a mouse tail model by increasing lymphangiogenesis and interstitial flow of the lymphatics by inhibition of the fibrosis. The differences in maximal tail thicknesses between the control and treatment groups were statistically significant from 2 to 4 weeks after surgery. The treatment group showed a greater number of lymphatic vessels at the surgery site than the control group. The treatment group also showed more FITC coverage area at the surgery site. Conclusion: EW-7197 treatment ameliorates acquired lymphedema in a mouse tail model by increasing lymphangiogenesis and interstitial flow.

A Canine Model for Lymphangiography and Thoracic Duct Access

OBJECTIVE

To evaluate the technical feasibility of intranodal lymphangiography and thoracic duct (TD) access in a canine model.

MATERIALS AND METHODS

Five male mongrel dogs were studied. The dog was placed in the supine position, and the most prominent lymph node in the groin was accessed using a 26-gauge spinal needle under ultrasonography (US) guidance. If the cisterna chyli (CC) was not opacified by bilateral lymphangiography, the medial iliac lymph nodes were directly punctured and Lipiodol was injected. After opacification, the CC was directly punctured with a 22-gauge needle. A 0.018-in microguidewire was advanced through the CC and TD. A 4-Fr introducer and dilator were then advanced over the wire. The microguidewire was changed to a 0.035-in guidewire, and this was advanced into the left subclavian vein through the terminal valve of the TD. Retrograde TD access was performed using a snare kit.

RESULTS

US-guided lymphangiography (including intranodal injection of Lipiodol [Guerbet]) was successful in all five dogs. However, in three of the five dogs (60%), the medial iliac lymph nodes were not fully opacified due to overt Lipiodol extravasation at the initial injection site. In these dogs, contralateral superficial inguinal intranodal injection was performed. However, two of these three dogs subsequently underwent direct medial iliac lymph node puncture under fluoroscopy guidance to deliver additional Lipiodol into the lymphatic system. Transabdominal CC puncture and cannulation with a 4-Fr introducer was successful in all five dogs. Transvenous retrograde catheterization of the TD (performed using a snare kit) was also successful in all five dogs.

CONCLUSION

A canine model may be appropriate for intranodal lymphangiography and TD access. Most lymphatic intervention techniques can be performed in a canine using the same instruments that are employed in a clinical setting.

Clinical effectiveness and safety of self-expanding metal stent placement following palliative chemotherapy in patients with advanced esophageal cancer

PURPOSE

To investigate the effect of prior chemotherapy on self-expanding metal stent (SEMS)-related complications in patients with locally advanced primary esophageal cancer.

MATERIALS AND METHODS

Data from patients with locally advanced primary esophageal cancer who received SEMS placement with or without prior chemotherapy were retrospectively reviewed. Patients were grouped according to prior palliative therapy: group A (n = 41) had received SEMS only, and group B (n = 64) had received palliative chemotherapy prior to SEMS placement. Patients' age, stricture length, tumor location, and dysphagia score prior to SEMS placement were evaluated. The overall patient cohort had a median follow-up period of 129 days (range 11-463). Outcomes after SEMS placement, including technical and clinical success rates, the occurrence of complications, and overall survival, were compared.

RESULTS

There were no significant differences between the two groups regarding patients' age, stricture length, tumor location, and dysphagia score prior to SEMS placement. SEMS placement was technically successful in all patients, with no procedure-related complications reported. Clinical success was achieved in 95.1% of patients in group A and 96.8% of patients in group B. The duration of stent patency was significantly shorter in group B [162 days; 95% confidence interval (CI) 126.6-198.4 vs. group A (339 days; 95% CI 258.8-419.3], p = 0.001. No significant differences were seen between the two groups regarding dysphagia score improvement [group A (3.15 ± 0.57 to 1.17 ± 0.83; p < 0.001) and group B (3.17 ± 0.80 to 1.14 ± 0.79; p < 0.001); p = 0.66], complications [group A (10/41), and group B (24/64); p = 0.094], or overall survival [the median and mean overall survival periods were 105 (95% CI 30-180) and 132 days (95% CI 97-167), respectively, in group A, and 126 (95% CI 88-164) and 156 days (95% CI 132-180), respectively, in group B; p = 0.592].

CONCLUSION

Prior chemotherapy did not increase the risk of complications following SEMS placement in patients with locally advanced esophageal cancer. SEMS patency was significantly longer in patients who did not receive chemotherapy prior to SEMS placement.

LEVEL OF EVIDENCE

Level 4, Case Series.

Rupture, Breakdown, and Pulmonary Artery Embolism of a Balloon Catheter Tip during Percutaneous Transluminal Angioplasty of Arteriovenous Fistula

Percutaneous transluminal angioplasty is a well-known treatment for arteriovenous fistula stenosis. Balloon rupture during endovascular procedures is a rare but possible complication. The bursting balloon itself does not cause a serious problem, but it can occasionally cause entrapment, especially in case of breakdown of the balloon catheter tip. Here, we present four cases of balloon rupture during angioplasty in the hemodialysis circuit. In three cases, the ruptured balloon catheter was removed by cutdown of access conduit, while in one case, tip of ruptured balloon catheter was migrated into the pulmonary artery and was removed surgically. The operator must attempt to reduce the risk of balloon rupture by gradually expanding the balloons under bursting pressure. If the balloon bursts, it should not be removed excessively and attempt should be made to remove it using endovascular techniques. Surgical removal is considered after careful evaluation of the condition of the balloon and vessel.

Fluoroscopic Balloon Dilation Using a Flexible Guide Wire to Treat Obstructive Eustachian Tube Dysfunction

PURPOSE

To prospectively evaluate the midterm outcomes of fluoroscopic eustachian tube (E-tube) balloon dilation by using a flexible guide wire in patients with obstructive E-tube dysfunction.

MATERIALS AND METHODS

From October 2016 to September 2017, adult outpatients with persistent otitis media who were unable to perform the Valsalva maneuver were prospectively enrolled. The analysis included 32 E-tubes from 31 patients (18 women, 13 men; mean age, 47 years old, range 25-72 years). Participants underwent fluoroscopic E-tube balloon dilation with a 0.035-inch flexible guide wire and a 6- × 20-mm balloon catheter. Clinical examinations to check for the ability to perform the Valsalva maneuver and otomicroscopy were conducted at 1 week and then at 1, 3, 12, and 18 months after the procedure.

RESULTS

Balloon dilation was technically successful in all E-tubes. The mean time required for the procedure was 6.9 minutes (range, 5.8-10.3 minutes). The Valsalva maneuver was successful in opening 25 of 32 E-tubes (78.1%) at 3 months after balloon dilation. During the median follow-up of 15.9 months, failure of the Valsalva maneuver occurred in 4 of 25 improved E-tubes (16%), yielding a 2-year patency rate of 84%.

CONCLUSIONS

The fluoroscopic balloon dilation results were encouraging, and using a flexible guide wire for E-tube balloon dilation did not cause a false passage.

Fully covered self-expandable esophageal metallic stents in patients with inoperable malignant disease who survived for more than 6 months after stent placement

OBJECTIVES

To investigate the clinical outcomes of fully covered self-expanding metal stent (FCSEMS) placement in patients with malignant esophageal obstruction who survived longer than 6 months.

METHODS

From January 2002 to January 2018, 88 FCSEMS were placed in 64 patients (mean age 62.9 ± 11.6 years; 58 males) with inoperable malignant esophageal obstruction with or without esophago-respiratory fistula. Only patients who survived more than 6 months with FCSEMS in place were included. Data regarding technical and clinical success, complications, reinterventions, stent patency, and patient survival were obtained from a prospectively maintained hospital database.

RESULTS

The technical and clinical success rates were 100 % (64/64). During follow-up, the median dysphagia score significantly improved (3.09 ± 0.68 to 1.05 ± 0.60, p < 0.001). The complication rate was 48.8 %. Multivariate analysis revealed that only longer stenting duration was associated with complications [hazard ratio = 1.220, 95 % confidence interval (CI) (1.074-2.760), p = 0.039]. The median follow-up duration was 257 days (range, 181-969). The median stent patency duration was 289 days [95% CI (209.9-368.1)]. The median survival was 254 days [95% CI (219.7-288.3)].

CONCLUSIONS

Our data suggest that esophageal FCSEMS placement is an effective option for patients with malignant dysphagia when survival longer than 6 months is expected. The rate of complications increases with time, and SEMS development is needed to keep up with the advancement in oncological treatment.

ADVANCES IN KNOWLEDGE

Fully covered esophageal self-expandable stent placement is effective in patients surviving more than 6 months, however, the rate of complications also increases. SEMS development is needed to cope with the advancement in oncological treatment.

Are patients with mild to moderate renal impairment on metformin or other oral anti-hyperglycaemic agents at increased risk of contrast-induced nephropathy and metabolic acidosis after radiocontrast exposure?

AIM

To investigate whether the use of metformin during computed tomography (CT) with radiocontrast agents increases the risk of contrast-induced nephropathy (CIN) and metabolic acidosis after CT in type 2 diabetes patients with mild to moderate renal failure.

MATERIALS AND METHODS

Patient records from January 2015 to December 2017 were reviewed retrospectively. A total of 374 patients were included in the final analysis. Of them, 157 patients received metformin, and 217 patients were taking other oral hypoglycaemic agents (OHAs) during radiocontrast administration.

RESULTS

No significant difference in CIN incidence was observed between the metformin use group and the other OHAs group (p=0.085). Metabolic acidosis after CT was seen in 91 (58%) patients who used metformin and 141 (65%) patients who were taking other OHAs. There was no relationship between metabolic acidosis after CT and the use of metformin (p=0.195). Metabolic acidosis after radiocontrast agent exposure was associated with malignant disease, low serum albumin level, and low serum total CO₂ level at baseline.

CONCLUSION

These data show that other factors, but not metformin use, are associated with metabolic acidosis after radiocontrast agent exposure in patients with reduced renal function. These data support current recommendations that there is no need to discontinue metformin before CT using radiocontrast agents in patients with mild to moderate renal failure.

Fluoroscopic self-expandable metallic stent placement for treating post-operative nonanastomotic strictures in the proximal small bowel: a 15-year single institution experience

OBJECTIVE

To evaluate the efficacy and safety of fluoroscopic self-expandable metallic stent (SEMS) placement for treating postoperative nonanastomotic strictures in the proximal small bowel.

METHODS

Data from 8 consecutive patients (mean age, 63.8 ± 6.9 years; 7 males and 1 female) who underwent 17 fluoroscopic SEMS placement procedures in total for treating postoperative nonanastomotic strictures in the proximal jejunum were retrospectively reviewed. The most recent surgery for all the patients was total gastrectomy with esophagojejunostomy. Strictures were located in the proximal jejunum in all patients. The mean length of the strictures was 5.8 ± 2.0 cm. Five patients with comorbidities were poor surgical candidates. Four patients underwent fluoroscopic balloon dilation, three of whom showed no resolution of obstructive symptoms and one demonstrated recurrence of symptoms.

RESULTS

Technical and clinical success was achieved in 100% (17/17) SEMS procedures. Complete resolution of obstructive symptoms and improvement in oral intake status occurred within 3 days after all procedures, rendering a clinical success rate of 100% (17/17). No complication occurred during or after the procedures. The median follow-up duration was 167 [interquartile range (IQR), 48-576] days. Stent malfunction occurred after 58.8% (10/17) of the procedures, including six occurrences of stent migration and four of benign tissue hyperplasia. Surgical removal of the migrated stents was performed in two patients. Recurrence of symptoms occurred after 64.7% (11/17) of the procedures. The median stent dwell and recurrence-free times were 32 (IQR, 20-193) and 68 (IQR, 38-513) days, respectively.

CONCLUSION

Fluoroscopic SEMS placement may be effective and safe for treating postoperative nonanastomotic strictures, but stent malfunction and recurrence are major drawbacks.

ADVANCES IN KNOWLEDGE

SEMS placement is effective and relatively safe in patients with postoperative nonanastomotic strictures in the proximal small bowel. Patients section and counseling is highly encouraged.

Abstract P4-01-11: Genomic alterations of cell-free DNA in early breast cancer patients with recurrence

Cell-free DNA (cfDNA), as a non-invasive strategy, provides substantial benefit to overcome tumor heterogeneity. Surveillance of recurrence after standard treatment in early breast cancer (BC) using cfDNA, enables to detect minimal residual disease (MRD), also to identify genomic alterations driving recurrences. We aimed to assess the role of cfDNA in detecting MRD by investigating genomic alterations of 1)primary, recurred tumor and 2)cfDNA at time of recurrence using deep targeted sequencing. Fifty-four early BC patients were enrolled prospectively between 2014 and 2017 at time of recurrence. Median disease free interval was 28.5 months (rage 6.2-49.8). 62.7% (32/51) were hormone receptor (HR) positive (28 HRpos/HER2neg, 4 HRpos/HER2pos), 11.8% (6/51) were HRneg/HER2pos and 25.5% (13/51) were triple negative BCs. 59.3% (32/54) patients developed loco-regional recurrence (15 local recurrence only, 13 regional only, 4 with both) and distant metastasis was observed among 40.7% (22/54) patients. Cell-free DNA was extracted from 5cc blood at time of recurrence. Deep targeted sequencing was performed using customized NGS panel –encompassing 426 cancer-related target coding region, 242 fusion and amplification-related region- of cfDNA and FFPE(formalin fixed paraffin embedded) tumor samples archived from surgical resection or biopsy. Deep targeted sequencing data was successfully performed in 72.1% (31/43) plasma samples and sequencing yield was significantly lower when stored for more than 2yrs (46.2% vs 83.3%).

Mutations of cfDNA and tumor (primary, recurred) were analyzed. Mean sequencing depth of cfDNA and FFPE were x425.7 and x777.6 respectively. Median number of pathogenic mutations found in primary tumor, cfDNA and recurred tumor were 27(range 12-99), 25(range 8-85) and 9(range 0-23). Among mutations found in primary tumor, 27.4% were shared mutations (range 8.1%-72.7%) with recurred tumor and 26.1% were shared mutations (range 4.7%-69.2%) observed in cfDNA sample. Among mutations found in recurred tumor, 40.9% were observed in cfDNA (range 17.7-87.5%). In primary tumor, median number of mutations with allelic fraction (MAF)&gt;10% were 12 (range 4-21) and at least one mutation was found in cfDNA at time of recurrence. Among mutations with MAF&gt;10%, 59.4% and 69.1% were found in cfDNA and recurred tumor. Known oncogenic mutations of PIK3CA, TP53, GATA3, AKT1, ESR1, RELN, ERBB2, ERBB3, BRCA1 mutation were found. PIK3CA gene (p.H1047R) was found in two cases both in primary tumor and cfDNA at recurrence (MAF 11.4% vs 5.3% and 12.3% vs 15.4%) suggesting de novo driver mutation. One patient developed regional recurrence during adjuvant aromatase inhibitor with ESR1 V392I mutation in both cfDNA and recurred tumor (MAF 48.1 and 54.5%), while another patient's recurred tumor during aromatase inhibitor harbored ESR1 D538G mutation exclusively in recurred tumor with MAF &lt;1%. Both patients had no ESR1 hotpot mutation in primary tumor.

Our data showed sequencing yield of 83.3% in plasma samples within 2yr. Pathogenic mutations in primary tumor, especially when MAF&gt;10%, half of them was observed in cfDNA at time of recurrence. ESR1 mutation should be included in cfDNA surveillance for patients undergoing endocrine therapy even absent in primary tumor.

Citation Format: Kim J, Jo WK, Kim KY, Kim BJ, Lee SB, Lee HJ, Yu JH, Kim HJ, Chung IY, Ko BS, Kim S-B, Jung KH, Ahn JH, Chang S, Lee JW, Son BH, Ahn SH. Genomic alterations of cell-free DNA in early breast cancer patients with recurrence [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-01-11.

In Vivo Fluorescence Microendoscopic Monitoring of Stent-Induced Fibroblast Cell Proliferation in an Esophageal Mouse Model

PURPOSE

To evaluate the feasibility of self-expanding metal stent (SEMS) placement and fluorescence microendoscopic monitoring for determination of fibroblast cell proliferation after stent placement in an esophageal mouse model.

MATERIALS AND METHODS

Twenty fibroblast-specific protein (FSP)-1 green fluorescent protein (GFP) transgenic mice were analyzed. Ten mice (Group A) underwent SEMS placement, and fluoroscopic and fluorescence microendoscopic images were obtained biweekly until 8 weeks thereafter. Ten healthy mice (Group B) were used for control esophageal values.

RESULTS

SEMS placement was technically successful in all mice. The relative average number of fibroblast GFP cells and the intensities of GFP signals in Group A were significantly higher than in Group B after stent placement. The proliferative cellular response, including granulation tissue, epithelial layer, submucosal fibrosis, and connective tissue, was increased in Group A. FSP-1-positive cells were more prominent in Group A than in Group B.

CONCLUSIONS

SEMS placement was feasible and safe in an esophageal mouse model, and proliferative cellular response caused by fibroblast cell proliferation after stent placement was longitudinally monitored using a noninvasive fluorescence microendoscopic technique. The results have implications for the understanding of proliferative cellular response after stent placement in real-life patients and provide initial insights into new clinical therapeutic strategies for restenosis.

Nanofunctionalized Stent-Mediated Local Heat Treatment for the Suppression of Stent-Induced Tissue Hyperplasia

Current therapeutic strategies are insufficient for suppressing stent-induced restenosis. Here, branched gold nanoparticles (BGNP)-coated self-expandable metallic stents (SEMSs) were developed for a local heat-induced suppression of stent-related tissue hyperplasia. Our polydopamine (PDA) coating on SEMS allowed BGNP crystal growth on the surface of SEMSs. The prepared BGNP-coated SEMS showed effective local heating under near-infrared laser irradiation. The effectiveness of BGNP-coated SEMSs for suppressing stent-related tissue hyperplasia was demonstrated in a rat esophageal model ( n = 52). BGNP-coated SEMS placement under fluoroscopic guidance was technically successful in all rats. The placed BGNP-coated SEMS in rat esophagus achieved three different local heat dose ranges (50, 65, and 80 °C) under fluoroscopic image-guided local irradiation. Follow-up endoscopic examination readily monitored the local heating and observed significantly decreased tissue hyperplasia at 4 weeks of local heat treatments (50 and 65 °C). Finally, Western blot, histology, immunohistochemistry (HSP70, αSMA, and TUNEL), and immunofluorescence (Ki67 and BrdU) analyses along with the statistical analysis confirmed that optimized BGNP-coated SEMS-mediated local heat treatments inducing the expression of anti-inflammatory HSP70 effectively suppresses tissue hyperplasia after stent placement in the esophagus. Our local heating with nanofunctionalized stents represents a promising new approach for suppressing stent-related tissue hyperplasia.

Fluoroscopic balloon diameter measurement at different pressures during Eustachian balloon dilation

OBJECTIVES

To measure the diameter of inflated balloons at different pressures during Eustachian tube (ET) balloon dilation under fluoroscopic guidance.

DESIGN

Prospective cohort study.

SETTING

Tertiary academic referral centre.

PARTICIPANTS

Eighteen patients who underwent ET balloon dilation with use of a balloon catheter, 20 mm long and 6 mm in diameter, under combined endoscopic and fluoroscopic guidance.

MAIN OUTCOME MEASURES

Degrees of inflation at three different portions (proximal, middle and distal) of the balloon at controlled pressures (3, 5, 8 and 10 atmospheres [atm]) and at the maximum pressure manually applied.

RESULTS

The mean proximal, middle and distal diameters of the inflated balloons were 5.3 ± 0.4 mm, 5.3 ± 0.4 mm and 4.9 ± 0.5 mm at 10 atm. The distal diameters were significantly smaller than middle and proximal diameters at all the pressures (P < 0.01). When compared to the distal diameter (100%, 4.9 ± 0.5 mm) at 10 atm, the distal diameters were 73% (3.6 ± 0.6 mm) at 3 atm, 88% (4.3 ± 0.5 mm) at 5 atm and 96% (4.7 ± 0.4 mm) at 8 atm. The distal diameter (4.1 ± 0.3 mm) at the maximum pressure manually applied was in between those at 3 and 5 atm.

CONCLUSIONS

The distal diameter of the balloon increased significantly as a function of the pressure and most (88%) inflation occurred at a low pressure of 5 atm, which was sufficient to inflate the distal diameter of the balloon more than 3 mm. The manual pressurisation could inflate a balloon by as much as could be expected, at between 3 and 5 atm.

Fluoroscopy-Guided Peroral Placement of a Self-Expandable Metallic Stent for Malignant Jejunal Obstruction in a Non-surgically Altered Stomach

Malignant small bowel obstruction is a common and distressing complication in advanced cancer patients. Recently, stent placement was reported to be a safe and effective alternative treatment. However, there are only a few case reports associated with stent placement in malignant jejunal obstruction. Furthermore, most patients had a history of gastrectomy before stent placement, which shortens the catheterization pathway. In our case series, we present five cases of malignant proximal jejunal obstruction in a non-surgically altered stomach in the management of fluoroscopy-guided self-expandable metallic stent placement and discuss the interventional management and clinical outcomes. LEVEL OF EVIDENCE: Level 4, Case Series.

Transnasal Placement of a Balloon-Expandable Metallic Stent: Human Cadaver Study of the Eustachian Tube

PURPOSE

To investigate the technical feasibility of stent placement in the cartilaginous portion of the Eustachian tube (ET).

MATERIALS AND METHODS

Twelve ETs of 6 cadavers were used. Two different-sized stents were placed on either the right (2.5 mm in diameter) or left (3.5 mm in diameter) side of the ET. The procedural feasibility was assessed by subtraction Eustachian tubography, computed tomography before and after the procedure, and fluoroscopic and endoscopic images. The stent location, inner luminal diameter of the stented ET, radiation dose, procedural time, and fluoroscopy time were analyzed.

RESULTS

Stent placement was successful in 11 of 12 cadaveric specimens without procedure-related complications. In the 1 specimen, the balloon catheter with crimped stent was passed into the bony canal of the ET without any resistance. The distal end of the stent was located in the middle ear cavity. Stents were located within the cartilaginous portion of the ET (n = 1), the proximal tip bridging the nasopharyngeal orifice of the ET (n = 5), or the proximal end of the stent protruded from the tubal orifice (n = 5). The mean luminal diameter in the outer segment was significantly smaller than in the middle (P < .001) and inner (P < .001) segments. The mean procedure time was 128 ± 37 seconds. The mean radiation dose and fluoroscopy time of each cadaver were 3235.4 ± 864.8 cGy/cm² and 139 ± 49 seconds, respectively.

CONCLUSIONS

Stent placement of the ET under endoscopic and fluoroscopic guidance is technically feasible in a human cadaver model.

Ischemic Preconditioning Produces Comparable Protection Against Hepatic Ischemia/Reperfusion Injury Under Isoflurane and Sevoflurane Anesthesia in Rats

BACKGROUND

Various volatile anesthetics and ischemic preconditioning (IP) have been demonstrated to exert protective effect against ischemia/reperfusion (I/R) injury in liver. We aimed to determine whether application of IP under isoflurane and sevoflurane anesthesia would confer protection against hepatic I/R injury in rats.

METHODS

Thirty-eight rats weighing 270 to 300 grams were randomly divided into 2 groups: isoflurane (1.5%) and sevoflurane (2.5%) anesthesia groups. Each group was subdivided into sham (n = 3), non-IP (n = 8; 45 minutes of hepatic ischemia), and IP (n = 8, IP consisting of 10-minute ischemia plus 15-minute reperfusion before prolonged ischemia) groups. The degree of hepatic injury and expressions of B-cell lymphoma 2 (Bcl-2) and caspase 3 were compared at 2 hours after reperfusion.

RESULTS

Hepatic ischemia induced significant degree of I/R injuries in both isoflurane and sevoflurane non-IP groups. In both anesthetic groups, introduction of IP dramatically attenuated I/R injuries as marked by significantly lower aspartate aminotransferase and aminotransferase levels and better histologic grades compared with corresponding non-IP groups. There were 2.3- and 1.7-fold increases in Bcl-2 mRNA levels in isoflurane and sevoflurane IP groups, respectively, compared with corresponding non-IP groups (both P < .05). Caspase 3 level was significantly high in the isoflurane non-IP group compared with the sham group; however, there were no differences among the sevoflurane groups.

CONCLUSIONS

The degree of hepatic I/R injury was significantly high in both isoflurane and sevoflurane groups in rats. However, application of IP significantly protected against I/R injury in both volatile anesthetic groups to similar degrees, and upregulation of Bcl-2 might be an important mechanism.

Developmental endothelial locus-1 prevents development of peritoneal adhesions in mice

Postoperative peritoneal adhesions, fibrous bands formed in the peritoneal cavity following surgery, represent a common, challenging and costly problem faced by surgeons and patients, for which effective therapeutic options are lacking. Since aberrant inflammation is one of the key mechanisms underlying peritoneal adhesion formation, here we set out to study the role of developmental endothelial locus-1 (Del-1), which has been recently identified as an endogenous inhibitor of inflammation, in the formation of postoperative peritoneal adhesions using a mouse model of peritoneal adhesions induced by ischemic buttons. Del-1-deficient mice had a higher incidence of adhesions, and their adhesions had higher quality and tenacity scores. Del-1 deficiency also led to enhanced inflammation mediators and collagen production. Finally, Del-1 supplementation decreased the incidence and severity of postoperative peritoneal adhesions. Taken together, these results indicate a protective role for Del-1 in postoperative peritoneal adhesion formation.

MeV electron acceleration at 1 kHz with <10 mJ laser pulses: erratum

In this erratum the funding section of Opt. Lett.42, 215 (2017)OPLEDP0146-959210.1364/OL.42.000215 has been updated.

Fluoroscopic Gastroduodenal Stent Placement in 55 Patients with Endoscopic Stent Placement Failure

PURPOSE

To evaluate the technical feasibility and clinical effectiveness of fluoroscopic self-expandable metal stent (SEMS) placement in malignant gastroduodenal obstructions after failed endoscopic SEMS placement.

MATERIALS AND METHODS

Between September 2010 and July 2017, 874 patients underwent endoscopic SEMS placement for dysphagia caused by malignant gastroduodenal obstructions. Endoscopic SEMS placement failed in 55 of 874 patients (6.3%). These patients were referred for fluoroscopic SEMS placement. In case of failed fluoroscopic SEMS placement, combined endoscopic and fluoroscopic SEMS placement was attempted at the same setting.

RESULTS

Fluoroscopic SEMS placement was technically successful in 40 of 55 patients (72.7%). Combined endoscopic and fluoroscopic SEMS placement was technically successful in 6 of 15 patients with fluoroscopic SEMS placement failure. Failures in the nine patients were due to complete obstruction (n = 5) and acute angulation at the stricture site (n = 4). The overall technical success rate was 83.6% (46/55). Clinical success was achieved in 95.6% of patients (44/46). Complications occurred in 7 of 46 patients (15.2%), including tumor overgrowth (n = 3), SEMS migration (n = 3), and bleeding (n = 1). The median SEMS patency and patient survival periods were 515 (95% confidence interval (CI), 266.6-761.5) and 83 (95% CI 60.6-105.4) days, respectively.

CONCLUSIONS

Fluoroscopic SEMS placement is technically feasible and clinically effective in cases of endoscopic SEMS placement failure. A combined endoscopic and fluoroscopic approach increases the technical success rate after failure of the endoscopic or fluoroscopic approach.

LEVEL OF EVIDENCE

Level IV.

Radiation-induced esophageal strictures treated with fluoroscopic balloon dilation: clinical outcomes and factors influencing recurrence in 62 patients

Background Balloon dilation is safe and effective for the treatment of radiation-induced esophageal stricture (RIES), with favorable short-term and mid-term outcomes; however, few reports of long-term outcomes exist. Few studies have evaluated factors associated with recurrence after balloon dilation. Purpose To evaluate the long-term outcome of balloon dilation in patients with RIES and to identify factors associated with stricture recurrence. Material and Methods The medical records of 62 consecutive patients who had undergone fluoroscopic balloon dilation for RIES at our institution between December 1998 and June 2016 were reviewed. Results One hundred and twenty balloon dilation sessions were performed in 62 patients (mean = 1.9 sessions per patient). Clinical success was achieved in 53 (86%) patients after single (n = 37) or multiple (n = 16) dilation sessions. Complications occurred in 27% of the dilation sessions. The primary patency rates at one, two, three, and five years were 60%, 56%, 52%, and 52%, respectively. Secondary patency rates at one, two, three, and five years were 87%, 85%, 85%, and 80%, respectively. Multivariate logistic regression analysis identified an interval from radiation therapy (RT) to stricture of ≥6 months (hazard ratio [HR] = 0.205; P < 0.001), strictures located at the cervical esophagus (HR = 5.846; P < 0.001), and stricture length of ≥2 cm (HR = 2.923; P = 0.006) as significant predictors of recurrence. Conclusion Despite the high incidence of ruptures and recurrences, fluoroscopic balloon dilation is valuable as an initial therapeutic option for patients with RIES.

EW-7197 eluting nano-fiber covered self-expandable metallic stent to prevent granulation tissue formation in a canine urethral model

PURPOSE

To evaluate an EW-7197-eluting nanofiber-covered stent (NFCS) for suppressing granulation tissue formation after stent placement in a canine urethral model.

MATERIALS AND METHODS

All experiments were approved by the committee of animal research. A total of 12 NFCSs were placed in the proximal and distal urethras of six dogs. Dogs were divided into two groups with 3 dogs each. The control stent (CS) group received NFCSs and the drug stent (DS) group received EW-7197 (1000 μg)-eluting NFCSs. All dogs were sacrificed 8 weeks after stent placement Histologic findings of the stented urethra were compared using the Mann-Whitney U test.

RESULTS

Stent placement was technically successful in all dogs without procedure-related complications. On urethrographic analysis, the mean luminal diameter was significantly larger in the DS group than in the CS group at 4 and 8 weeks after stent placement (all p < 0.001). On histological examination, mean thicknesses of the papillary projection, thickness of submucosal fibrosis, number of epithelial layers, and degree of collagen deposition were significantly lower in the DS group than in the CS group (all p < 0.001), whereas the mean degree of inflammatory cell infiltration was not significantly different (p > 0.05).

CONCLUSION

The EW-7197-eluting NFCS is effective and safe for suppressing granulation tissue formation after stent placement in a canine urethral model.

Effect of Changes in Body Mass Index on Cardiovascular Outcomes in Kidney Transplant Recipients

BACKGROUND

A higher body mass index (BMI) before kidney transplantation (KT) is associated with increased mortality and allograft loss in kidney transplant recipients (KTRs). However, the effect of changes in BMI after KT on these outcomes remains uncertain. The aim of this study was to investigate the effect of baseline BMI and changes in BMI on clinical outcomes in KTRs.

METHODS

A total of 869 KTRs were enrolled from a multicenter observational cohort study from 2012 to 2015. Patients were divided into low and high BMI groups before KT based on a BMI cutoff point of 23 kg/m². Differences in acute rejection and cardiovascular disease (CVD) between the 2 groups were analyzed. In addition, clinical outcomes across the 4 BMI groups divided by BMI change 1 year after KT were compared. Associations between BMI change and laboratory findings were also evaluated.

RESULTS

Patients with a higher BMI before KT showed significantly increased CVD after KT (P = .027) compared with patients with a lower BMI. However, among the KTRs with a higher baseline BMI, only persistently higher BMI was associated with increased CVD during the follow-up period (P = .003). Patients with persistently higher BMI had significantly decreased high-density lipoprotein cholesterol and increased hemoglobin, triglyceride, and hemoglobin A1c levels. Baseline BMI and post-transplantation change in BMI were not related to acute rejection in KTRs.

CONCLUSIONS

BMI in the 1st year after KT as well as baseline BMI were associated with CVD in KTRs. More careful monitoring of obese KTRs who do not undergo a reduction in BMI after KT is required.

Cystatin C-Based Equation for Predicting the Glomerular Filtration Rate in Kidney Transplant Recipients

BACKGROUND

Precise monitoring of the glomerular filtration rate (GFR) is needed to estimate the allograft function in kidney transplant recipients (KTRs). The GFR is widely estimated with the use of formulas based on serum cystatin C (SCys) and serum creatinine (SCr) levels. We compared the efficacy of SCys-based equations with that of SCr-based equations to predict the allograft function.

METHODS

We calculated the Modification of Diet in Renal Disease (MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI Cr), CKD-EPI creatinine-cystatin C (CKD-EPI Cr/Cys), and CKD-EPI cystatin C (CKD-EP ICys) equations in 70 KTRs. The measured GFR (mGFR) was defined as the GFR estimated by technetium-99m-diethylene triamine pentaacetic acid (^99mTc-DTPA) clearance. The accuracy and precision of the equations were compared with the mGFR. The performance characteristics of SCr and SCys were analyzed with the use of receiver operating characteristic (ROC) curves to ascertain the sensitivity and specificity at the cutoff value of <45 mL/min/1.73 m² DTPA.

RESULTS

Overall, MDRD and CKD-EPICys did not show significant differences from mGFR (P = .05 and P = .077, respectively), whereas CKD-EPI Cr and CKD-EPI Cr/Cys significantly underestimated mGFR (P < .001 and P = .005, respectively). In the subgroup of patients with mGFR <45 mL/min/1.73 m², CKD-EPI Cys showed little bias (P = .122), whereas MDRD significantly underestimated mGFR (P = .037). The area under the ROC curve for predicting mGFR <45 mL/min/1.73 m² was 0.80 for SCys, which was better than that for SCr at 0.763.

CONCLUSIONS

Cystatin C-based equations showed better predictive performance of the allograft function than creatinine-based equations for the KTRs, including patients with lower GFR. Cystatin C level might be a good alternate measurement to monitor the allograft function.

Use of metal/metal oxide spherical cluster and hydroxyl metal coordination complex for descriptor calculation in development of nanoparticle cytotoxicity classification model

Computational approaches have been suggested as an informative tool for risk assessment of nanomaterials. Nano (quantitative) structure-activity relationship, nano-(Q)SAR, models have been developed to predict toxicity of metal oxide (MOx) nanoparticles (NPs); however, the packing structure and cluster of nanoparticle have been included for the descriptor calculation in only two studies. This study proposed spherical cluster and hydroxyl metal coordination complex to calculate descriptors for development of nanoparticle cytotoxicity classification model. The model cluster was generated from metal (M) or MOx crystal structure to calculate physicochemical properties of M/MOx NPs and the hydroxyl metal coordination complex was used to calculate the properties of the metal cation in an aqueous environment. Data were collected for 2 M and 19 MOx NPs in human bronchial epithelial cell lines and murine myeloid cell lines at 100 μg/ml after 24 hours exposure. The model was developed with scaled HOMO energy of the model cluster and polarizability of the hydroxyl metal coordination complex, as reactivity of the particles and the cations explained cause of cytotoxic action by M/MOx NPs. As the developed model achieved 90.31% accuracy, the classification model in this work can be used for virtual screening of toxic action of M/MOx NPs.